Openapi GitHub Repositories (2026) · Open Source Tools

🧡 Turn your API spec into type-safe code. Generate TypeScript types, API clients, hooks, validators and mocks from a spec such as OpenAPI.

OpenAPI based HTTP Client code generator

Terminal API client for HTTP, GraphQL, gRPC, WebSocket and SSE. Plain .http files you can diff and version, with scripted tests, workflows, mocks, recorder, and a CLI runner for CI.

Modern data layer for TypeScript apps - type-safe ORM, built-in access control, automatic query services

Next generation noIM application in your own workspace, not only another Slack/Discord/Rocket.chat

Input OpenAPI. Output SDKs and Docs.

Platformatic Open Source monorepo!

Light, flexible and extensible ASGI framework | Built to scale

multimodal routing, geocoding, and map tiles

The OpenAPI.NET SDK contains a useful object model for OpenAPI documents in .NET along with common serializers to extract raw OpenAPI JSON and YAML documents from the model.

Simulate API failures, throttling, and chaos — all from your command line.

The open source, cloud native tool for API Mocking and Testing. Microcks is a Cloud Native Computing Foundation incubating project 🚀

Every API has a secret identity. This finds it, absorbs every feature from every competing tool, then builds the GOAT CLI — designed for AI agents first, with SQLite sync, offline search, and compound insight commands.

💨 Fast, Async-ready, Openapi, type hints based framework for building APIs

🕸️ Create REST and GraphQL APIs, scaffold Jamstack webapps, stream changes in real-time.

gRPC to JSON proxy generator following the gRPC HTTP spec

Mockoon is the easiest and quickest way to run mock APIs locally. No remote deployment, no account required, open source.

Examples and server integrations for generating the Swagger API Specification, which enables easy access to your REST API

Design-first Go framework that generates API code, documentation, and clients. Define once in an elegant DSL, deploy as HTTP and gRPC services with zero drift between code and docs.

Typesafe APIs Made Simple 🪄